This invention relates to a novel crystalline hydrate useful as a sequestering agent for metal and alkali earth metal ions and as a builder ingredient in detergent formulations.
It is known that the compound ##STR1## (trisodium carboxy methoxy malonate) is a useful sequestrant and detergency builder. (See, for example, U.S. Pat. No. 3,865,755).
The tendency of the anhydrous amorphous material to adsorb water under conditions of high relative humidity may cause problems in powdered or granular detergent formulations containing the material as a builder. It is additionally known that detergent formulations generally exhibit optimum performance in basic solutions. Therefore, such formulations frequently contain sufficient base to raise the pH of the system in which the formulation is to be employed. The use of additional ingredients such as the base may introduce problems of non-homogeneity of the formulation via settling and stratification of ingredients unless the ingredients are correlated with respect to particle size and density or unless agglomerating procedures are employed to combine the ingredients into composite granules.
Therefore, the desirability of a crystalline relatively non-hygroscopic material possessing the functional characteristics of trisodium carboxy methoxy malonate and being capable of integral compositing with bases will be recognized by those skilled in the art.